The present invention relates generally to side curtain airbags used for side impact and rollover protection, although the designs also may be useful in other airbag application types.
Side curtain airbags generally deploy downward from a stowed position within the roofline of vehicle and inflate between the occupant and the vehicle interior side structure, such as the side windows and the A, B and/or C pillars.
A side curtain airbag generally consists of two fabric panels either sewn or interwoven together to create inflatable cells. These cells are inflated during an accident to provide the desired side restraint. A side curtain may have a plurality of cells in various arrangements. Typically, inflatable cells in the range of two inches to as much as eight inches in inflated thickness may be created by sewn or interwoven seams connecting the fabric layers. The cell's inflated thickness (or curtain thickness) is the distance between the two fabric panels when inflated.
Conventional airbag curtain designs have “open flow” between chamber cells. Open flow is characterized by the gas within a cell having substantially open fluid communication with adjacent cells. This configuration allows the gas to uniformly fill the entire airbag because the gas distributes among all of or most all of the airbag cells or inflated regions. An example of an open flow conventional airbag is disclosed in FIG. 2 of U.S. Pat. No. 6,481,743 to Tobe et al., the entire disclosure of which is herein fully incorporated by reference.